Emitters have a wide range of potential applicability in the microelectronics field. An emitter emits electrons in response to an electrical signal. The controlled emissions form a basis to create a range of useful electrical and optical effects. Prior conventional emitters include spindt tip cold cathode devices as well as flat emitters.
Challenges presented by spindt tip emitters include their manufacturability and stability over their service life. Manufacturing of spindt tip emitters requires a number of relatively difficult deposition steps, with the result that it is generally expensive and time consuming. Once formed, a tip may be unstable as it can change as it is operated, and is subject to damage if not operated in high vacuum.
Traditional flat emitters are comparably advantageous because they present a larger emission surface and can be operated in less stringent vacuum environments. Flat emitters include a dielectric emission layer that responds to an electrical field created by a potential applied between an electron source and a thin metal layer on either side of a dielectric layer. Electrons travel from the electron source to the conduction band of the dielectric somewhere in the dielectric layer. Once into the conduction band, the electrons are accelerated towards the thin metal. The electrons then travel through the thin metal and exit the emitter.
Problems and unresolved needs remain with flat emitters, however.